The present invention relates to a color video printer, and more particularly to a method for easily notifying a user of the printing status of a color video printer by displaying the printing status of the color video printer at that time.
Generally, in a color video printer, the printing status can be seen by a user, but techniques for more easily displaying the printing status have been demanded.
FIG. 1 shows a block diagram of a conventional color video printer. If a composite video signal is applied to a Y/C separator 1 from an input terminal 1H, the Y/C separator 1 separates the video signal into a luminance signal and a chrominance signal. A first switch 2 is for selectively switching a signal generated from the Y/C separator 1 or a super video signal applied to an input terminal 2H. A decoder 3 converts a signal selected by the first switch 2 into color difference signals R-Y, B-Y and Y, and a second switch 4 selectively transmits the color difference signals R-Y, B-Y and Y to a memory 6 or a third switch 7 in response to a control signal of a switching controller 5. The third switch 7 selects an output signal of the memory 6 or the second switch 4 in response to the control signal of the switching controller 5. A decoder 8 separates the received color difference signal into chrominance signals R (Red), G (Green) and B (Blue), and a fifth switch 12 sequentially selects the chrominance signals R, G and B in the order of B, R and G depending on the printing order. Then, an A/D (Analog-to-Digital) converter 13 converts the chrominance signals B, R and G received from the fifth switch 12 into a digital signal in response to a clock pulse supplied from an external clock generator. The digitally converted chrominance signal is stored into a line memory 14 and is pulse width converted by an intermediate converter 15. Then, in a TPH (Thermal Printing Head) unit 16, the color printing is carried out in response to the pulse width converted chrominance signal. In this case, color components Y (Yellow), M (Magenta) and C (Cyan) are sequentially printed. Meanwhile, the chrominance signals R, G and B produced from the decoder 8 are again converted into a composite video signal by an encoder 9 and the composite video signal is applied to a fourth switch 10. Moreover, a pedestal level signal of a pedestal level input terminal PL is also applied to the fourth switch 10. In response to a control signal of a monostable multivibrator 11, the fourth switch 10 generates the pedestal level signal with respect to a portion being printed, and generates the composite video signal with respect to the portion that is not being printed. The signals generated by the fourth switch 10 are then displayed on a screen monitor. Therefore, on the screen monitor, the portion being printed is indicated by a black bar indicative of the pedestal level signal. Thus, since the portion being printed is displayed by a black bar and the other portion is displayed by a corresponding composite video signal, irrespective of the colors Y, M and C, the user cannot know what color is being printed.